<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <link href = "../btn_css/btn.css" rel = "stylesheet" />
</head>
<body>
    <input type ="button" value = "按钮1" />
    <input type ="button" value = "按钮2" />
    <input type ="button" value = "按钮3" />

</body>
</html>